import numpy as np
import pandas as pd
from matplotlib.pyplot import show

nan=np.nan
df=pd.DataFrame(dict(A=[1.1,2.2,nan,4.5,5.7,6.9],
                     B=[.21,nan,nan,3.1,11.7,13.2]))
df.interpolate().plot()
df.interpolate().plot(kind='bar')
show()
